Radio system



y 1952 R. H. RANGER 2,603,777

' RADIO SYSTEM Filed Feb. 25, 1944 3 Sheets-Sheet l FIXED PIVOT I I lvvewrae P/ CHAQQ hf 184N651? QJJQLQQ drrozzwvg):

July 15, 1952 R. H. RANGER 2,603,777

RADIO SYSTEM Filed Feb. 25, 1944 3 Sheets-Sheet 2 ,2 INl/E/vfaf a/MM Q4741!- July 15, 1952 RANGER 2,603,777

RADIO SYSTEM Filed Feb. 25, 1944 3 Sheets-Sheet 3 Qxcwneo h. ewvae? ,4:- rae wrr Patented July 15, 1952 uN TEojisTArEs PATENT. OFFICE Richard H. Ranger, United States Army;

- Newark, N. J.

" ApplicationFebruary 25, 1944;Seria'l No. 523,930 9Glaims';' (o1. 343%11).

(Granted under. the act of March 3, 1883,. as V amended-April 30, 1928; 3'70 OLG. 757).

IV Theinvention describedherein may. be manufactured and usedby or for; the Government for. governmental purposes, without the payment to me of. any. royalty thereon.

Thisi-invention-relates.to devices for locating and. determining the distance of aircraft and other objects from a definite station; and to pro.- vide information to enablean: observer to predict the.= future movementsrofthe. aircraft;

Devices. of the radio: object locator. type have beene-used. heretofore to. determine; the instanitaneousxposition and distance. of aircraft, but such determinations are: insufficient should the. aircraft change its course or resort tocert'ain evasive-actions. V

I It. is. an object of this; inventionv to provide apparatus by means. ofwhich an observerskilled ina-the manipulation of military aircraft is en.-- abled to. predict thelactions'. of an enemy aircraft overza known terrain. 1

Afurther-object is the provision of: adevice for determining simultaneously the azimuth; altitude and; horizontal distance of 3 aircraft from a fixe'd station; .together withthe straight line distance. ;A further object is the .provisi'onof a devicefor use-in-connection with radio object'locator apparatus for-locating aircraft and thereafter fol-" lowingithe. movements of the aircraft whereby the. actions ofthe aircraft: canbe'predicted; 7

Theseand'otherobjects are attained by'the' novel arrangements and methods hereinafter described and illustrated by the accompanying drawings; in which: u 1

Fig. 1 is a perspective-view Ora-device embodyingr-theinvention.

Fig. 2 is an enlarged perspective elements: of the device; a H

@Figa3 isaside elevationalzview tof thedevice;

view of certain Referri nguto the drawings; the" apparatus is shown-to comprise a table. I :I having :ro'tatablymounted-thereon adisc I2 covered with amapi of the particular terrain under consideration. Pivotallyaconnected-to the table -,II are a pairv of upstanding'arms Iii-connected by across bar I4 whiehssupports a frame I5 carrying a halfsil vered mirror- I6havingtransparent and refiect ingQprQpertieS. Mounted on' the cross bar I4 is aniipstandingstaff Ilsupporting a cathode raytube lfihaving a face I9, provided with a datum line ,Z'Ilhavingan initial mark at 52. The'face or scre'enportion I9 of the tube is substantiallyparallellto the disc when the arms I3 are vertical. In thi'srplositionrthe axis of the tube is parallel with theaxis of rotation of the disc. Q

Ther mapon disc. I2 is also providedwith a datum line which initially is alined withamark 8I on the table. A plate of transparent material 22, having markings thereon, has its lower edge: 2I initially in alinement with the datum line- 80 on the map.- The plate 22 is pivoted about theaxis of rotation of; the disc and map and projects upwardly perpendicular to; the. disc I2.

The: cathode. ray tube is connected to. radio object. locator apparatus 53, emitting very; high frequency radio waves whichv are directed towards an aircraft'or other object When the Waves strike. the aircraft, they are reflected back to areceiver forming apart of the radio: object locator. apparatus; the receiverbeingconnected-to the-cathoderaytube: The reflected waves produce a pipon the face .of the cathode ray tube; andthe distance away; of the-aircraft is indicated by the.distance of the pipi 5| on the datumline 20 from the initial mark 52.

The radio-object locator-device 53 is pivotally" mounted one post-24 forv rotary movements inza vertical plane, and thepost- 24 is mounted for rotary movements in ahorizontal plane" on-a pedestal'25. Fixed to post-24 is a gear 26- in mesh with. a gear 21- of the-same size; the latter: gear being .fixedto the shaftof a selsyn' -motor 28 which is electrically connected to a Selsyn motor 29 .having fixed to its shaft a gear 30' in mesh with a similar gear 3I fixed to shaft 32 upon which thedisc I2 is mounted. By means-of. this structure the disc I2 is caused to follow exactly thehorizontal rotary movements of the post 24 and. thus indicatethe azimuth of the object-being located. i

It is to be noted that clockwiserotationof the radar azimuth is connected to givecounterclockwise rotation :of themap disc I2, so that the image of datum line 20 Will'be oriented correctly with respect to the map. v

Carried by the radio object locator device 53 and moving in a vertical plane is a segmental gear The transparent plate 22 has'm'arked' thereon horizontal lines I'Iv to indicate altitudes, and vertical lines I2 to indicate horizontal distances. When the face I9. ofthe cathoderay tube and the mirror I6 are parallel with the disc I2, the

the axis of the tube is parallel with the axis of 1Q rotation of the map.

The relative positions of the image of datum line 20 and edge 2| and the construction of the device is such that the image and .edge determine a plane surface which is perpendicular to the plane of the map as the arms l3 and the cathode 1 ray tube are rotated in elevation corresponding to elevation control from the radio object locator. apparatus 53. The axis of the cathode ray tube is inclined to the axis of rotation of the map resulting from the pivoting of the arms on the table. The cathode ray tube is connected to the radio object locator apparatus in such a manner that a pip 5| appears along the datum line of the screen -'|9 a distance from the initial mark 52 proportional to the slant height of the aircraft orother object. The scale of distance along the screen datum line 20 is the same as the scale of the map. That is, if one inch represents 10 miles on the map, one inchfrom mark 52 on the datum line 20 will represent 10 miles. The position of a pip 5| on the datum line 20 indicates the direct distance of the object from the radar device and the horizontal distance of the object will be the vertical projection of this distance on to the map.

1 In operation, when an aircraft or other object has been located by the' radio object locator ap paratusthe disc l2 with the map will be rotated by the Selsyn motor 29 in inverse synchronism with the horizontal rotation of the radar appara- 40 tus and the definite azimuth angle Willbe indicated by markings'on the table and map. The distance away of the object is shown by the position of the pip 5| (see Fig. 2) on the reflection of the datum line 20 in the mirror i6. An observer looking into the half-silvered mirror sees avirtual image of the datum line 20 of the screenjof the cathode ray tube and thepip 5|, indicating the direct distance away 'of the aircraft or other object being observed. The observer'views the reflection of the line 20 in the mirror It and simultaneously views edge 2|, 'obtaininga composite View in which the reflected line 2|lapp ears to lie on the transparentsheet 22. When the face of the cathode ray tube is parallel with the map, the image of datum line 20 will be parallelwith edge 2|. As the aircraft gains in altitude, the Selsyn motors 35 and 36connected to the radar apparatus and the arms l3 willtilt the axis of a the cathode ray tube and in consequence the reflection of datum line 20 away from the-map datum line 2|. An observation in the mirror will now. havean automatic correction for slant height since the pip 5| which represents the aircraft will appear to be suspended in space a distance above the plane of the map which corresponds in scale to the altitude of the aircraft. The image of datum line 20. will appear to meet the edge 2| at the center of the map and thence diverge therefrom at an angle dependent upon the amount of tilting of the cathode ray tube. The point where pip 5| strikes a vertical line on the transparent sheet 22 indicates the horizontal distance of the object; and where the pip 5| guns for anti-aircraft fire.

strikes a horizontal line indicates the altitude of the object.

There are also traced on the sheet 22 (as shown particularly in Fig. 3) a family of trajectories 93 intersecting the vertical and horizontal lines. These trajectories 93 represent possible shell paths from anti-aircraft guns located at the observation station which is taken to be the axis of v.rotation of the map.

In predicting the actions of an approaching aircraft, there are employed two or three observers who have had previous experience as skilled pilots and are familiar with the logical actions of various aircraft over the type of terrain under consideration, observers knowing exactly the positions of objects in the terrain which might be subjected to bombings. The observers note 7 the location of the aircraft at short intervals,

such as 10 seconds, and in this manner are able to determine the course of the aircraft as well as its mode of flying. Each observer makes his analysis of the situation, and action is takenupon the most logical of the analyses.

A timing device is placed into operation immediately upon the first location of the aircraft, the device giving a signal at 10 second intervals and the observers mark the position and altitude of the aircraft at each signal by markers 94 on the map. (See Fig. 1.) These markers 94 record the horizontal distance and the altitude of the aircraft, and the azimuth thereof,-at eachinterval. The wind velocity can be determined by any well known means and should be taken into account. C

One end of the transparent plate 22 is pivoted at the center of the disc I2 and the other end has fixed thereto a segmental gear 6|, in mesh with a pinion 62, fixed to a vertical shaft 63 having a knob 64. By means of this structure the position of the transparent plate 22 can be finely adjusted, and may be moved forward or back from the active vertical datum plan to'assist prognosticating where the aircraft will be and which trajectory will strike that estimated point, considering the time involved for the shell to get to the same point as the aircraft. Lines indicating fixed times of fuse setting may also be marked on the transparent plate to aid fuse setting information. -The particular trajectory to be used is determined by noting upon which trajectory line 93 the image of pip 5| falls. (See Fig. 2.)

The angle of the trajectory which it is estimated will strike the plane is likewise giventhe The invention having been described, What is claimed is:

v 1. A device for automatically deriving the components horizontal range and altitude 0f "an object from slant range as determined'b'y a radio object locator comprising, a base member; a range plate having a plane surface supported in a vertical plane on said base and having inscribed thereon a; system of rectangular coordinate lines having an origin and extending in horizontal and vertical directions and representing to a' predetermined scale altitude and rangei object.

range indicator including a' fluorescent screen and means adapted to display thereon a luminous mark indicating slant range and a datum line defining the deflection path of said luminous range mark; a half-silvered mirror; means'for adjustably supporting said range indicator and mirror for rotation about a horizontal axis through the origin on said range plate and perpendicular to the plane thereof, the indicator and to said indicator supporting frame for positioning said supporting frame in accordance with the elevation of the object, a zero mark and a datum line on the face of said range indicator, said range indicator adapted to display a luminous pip indicating slant range derived from said object locator and so positioned that when viewed by reflection from the upper surface of said halfsilvered mirror the said zero mark appears coincident with the origin on the range plate and the range pip on said datum'lineappears as a luminous spot on the range plate at a position corresponding to that of the object, whereby horizontal range and altitude may be read off the respective graduations and the proper gun elevation for the target read off the trajectory passing through said object position. i

7. A device for use in conjunction with a radio object locator for showing the space position of an object with reference to a map comprising, a table member supported in a horizontal plane, a circular disc carrying a map pivotally mounted on said table with its axis of rotation vertical,

means for positioning the disc in accordance with the azimuth of the object determined by a radio object locator, a range plate provided with horizontal and vertical graduations mounted on the table in a vertical plane above said disc the origin of said graduations lying on said vertical axis, a cathode ray range indicator having a zero mark and a datum line defining the path of a luminous mark indicating slant'range, a halfsilvered mirror, means for adjustably supporting said range indicator and mirror for rotation about a horizontal axis perpendicular to said range plate and through the origin thereon said mirror being positioned midway between said horizontal axis and the face of said indicator, said indicator being so positioned on said adjustable supporting means that when viewed by reflection from the mirror the zero mark on the indicator appears position of the object in space, in altitude, azi

muth'and horizontal range.

8. A device for'use in conjunction with a radio object locator for showing the space position of an object with reference to its position above a map in terms of horizontal range and altitude comprising a table member supported in a hori- 8. zontal plane, a circular disc pivotally mounted on said table with its axis of rotation preferably vertical, a map on said disc, self synchronous motor means connected to said radio locator and to said disc for positioning the disc in accordance with the azimuth of the object as determined by said radio object locator, a cathode ray slant range indicator and a half-silvered mirror supported on an upstanding frame pivotally mounted on the table with the axis of tilt passing horizontally through the center of said disc, a range plate having graduations giving horizontal range and altitude inscribed thereon mounted on the table with its plane perpendicular to said horizontal axis and the origin of the graduations being coincident with the center of said disc said mirror being positioned midway between said horizontal axis and the face of the indicator, self synchronous motor means connected to said object locator and to said upstanding supporting frame for positioning said supporting frame in accordance with the elevation of the object, a zero mark and a datum line inscribed on the face of said range indicator defining the path of a luminous pip indicating slant range derived from the object locator, said datum line lying in the plane of said range plate and said indicator being so positioned that when viewed by reflection from the upper surface of said half -silvered mirror said zero mark coincides with the origin on the range plate and the range pip appears as a luminous spot on the range plate at a position above the map corresponding to that of the object wherefrom horizontal range and altitude may be read off the respective graduations together with the true position on the map.

9. A device as defined in claim 8 having a series of trajectories inscribed on said range plate having a common origin and having horizontal range and altitude graduations inscribed thereon.

RICHARD H; RAN GER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,231,929 Lyman Feb. 18, 1941 2,426,184 Deloraine Aug. 26, 1947 2,430,292 Hershberger Nov. 4, 1947 2,440,250 Deloraine Apr. 27, 1948 2,444,771 Fyler July 6, 1948 2,518,968 WoliT Aug. 15, 1950 2,519,397 Ranger Aug. 22, 1950 

